90 mg of Mirtazapine (remeron) before bed CLEARLY enhanced my dreaming abilities !!! (The step before lucid dreaming)
What i mean by this is that your dream takes A LOT more information out of what your subconsciousness records during the day before that sleeping session. And one of the main keys to lucid dreaming is being able to make your subconsciousness register specific intel such as the so called "reality checks" (Am i seriously dreaming at this present moment?).
The thing is, your subconscious is pretty much very selective (it doesn't keep everything your perception gives you) and, by definition, not very easy to handle at free will. I believe it especially records the informations that trigger emotions in you. (For example, one day i was pretty anxious i may had gotten hiv/hepatites and that night my dream had a WHOLE scenario about me infecting my ex (another non neutral emotional information) with my (imagined) hepatite through intercourse).
Oh and the best psychedelic/dissociative/deliriant trips out there ressemble a lot to lucid dreaming itself.
(edit) Besides, Mirtazapine in an AWESOME somniferous because it enhances the very definition of the dream state : it makes hypnagogic imagery (the mere entrance to a dream) heaps more available to the, still, conscious mind, when normally these hypnagogic visuals occur during the very transition to the unconsious (not knowing you're dreaming).